Toast appeared in "Horrid Henry and the Green Machine". It was also a visible ingredient in the All-In-One Breakfast from "Horrid Henry, Time Manager".
In "Horrid Henry and the Green Machine", Henry goes to put the bread in the toaster, only to discover it is missing. Peter says they aren't using the toaster anymore, much to Henry's dismay.
In "Horrid Henry, Time Manager", Henry and Peter fight over a piece of toast in the beginning of the episode. Dad tells Henry to give the toast back to Peter.